Damn, I think this is the toughest question I've gotten yet! He absolutely would share similarities to Sakuya for sure, but there'd be a lot more different types of blades in his moveset. While Blake canonically uses mostly knives to fight, this is simply because knives are what are most abundant at the Scarlet Devil Mansion. He has an affinity for the majority of bladed weapons (axes, swords, etc.) I think that he would also be more "silly" and have pop culture references in his move set, as he canonically came from the outside world in modern times. One of the things I could think of is that he could use a gigantic leek as a part of his attacks! Here's a little fun lore fact; Blake actually keeps a small leek garden inside of his laboratory, as they are his favourite vegetables. I believe he'd also be lighter / move faster than Sakuya, while dealing more damage, but also having less health. A character that you could call a "lightning bruiser" that's also a glass cannon. Those are my initial thoughts, but I'd definitely like to think about this question more! I've wanted to make a Touhou fighting game in the distant future for fun, so we'll see how things play out.